Looking at the rules in1997:
https://en.wikipedia.org/wiki/1997_M...xpansion_draft
It reads: All players in an organization were eligible to be drafted, except those with no prior major league experience who had less than three years service if signed at age 19 or older, or had less than four years of service if signed at age 18 or younger.
Your man has MLB experience so he doesn't qualify. I realize that the line you are toggling is shortened in its descriptor to just the Pro Service part as a variable, but I think this is the rule it is trying to replicate.